This Is Us is one of NBC's trailblazing dramedy series, which clearly took viewers by surprise with its epic plot twist in the premiere episode. The show revolving around three storylines with one particular connection – three characters share the same birthday – returns this Tuesday (27 September) with episode 2 titled The Big Three. It remains to be seen how Kevin, Kate and Randall's stories unfold?

Click here to watch This Is Us season 1 episode 2 live online on the official NBC website. The Big Three will air on at 10pm EST.

Spoilers alert: Do not proceed if you have not watched the premiere episode.

The Big Three will open with a flashback scene where Jack and Rebecca have been through eight years of parenting three children. The synopsis reveals that raising three children starts to take a toll on the couple and in the present day each of the children struggle with their own issues.

Further, Kate will realise that losing weight is not that easy and her brother Randall may face new questions from his wife Beth about his newfound father William.

What seemed like a sweet family show dropped major bombs on viewers last week when it was revealed that Kevin – the unsuccessful actor, who just quit The Manny – his twin Kate, who is struggling with body weight issues and Randall – the businessman in search of his biological father – are actually siblings. The beautifully connected plot even dropped hints during the pilot episode suggesting an obvious connection between the characters, who were all turning 36 at the same time.

Watch the trailer for This Is Us episode 2 here:

The NBC series incorporated more than just one surprise element as it unveiled the storyline of Jack and his wife Rebecca (played by Milo Ventimiglia and Mandy Moore) in the flashback with a big twist. As it turns out the affectionate couple, who even indulged in a little birthday romance, actually lost one of their triplets during delivery.

But following a great performance by Gerald McRaney as the experienced doctor and the heart-warming "Lemonade" conversation between him and the new father, Jack and Rebecca walk out of the hospital with three kids – two of their own and one adopted. Eagle-eyed fans of the show sure would connect the dots and the relationship between the "big three".

To know what happens in the lives of these characters in the past and the present, catch up on the series this Tuesday on NBC.